The invention relates to an electromagnetic actuator designed to be used in an electric switch apparatus, and in particular in an apparatus of relay, contactor or automatic tripping contactor type.
In particular, the invention concerns an electromagnetic actuator for a switch apparatus comprising a fixed part, a moving part and an excitation coil,                the fixed part comprising a ferromagnetic yoke and a magnetized assembly composed of at least one magnet fixedly mounted on the yoke, the magnetized assembly extending in a direction substantially parallel to an axis of movement of the moving part,        the moving part comprising a ferromagnetic element comprising a first air-gap surface to form a magnetic air-gap of variable thickness with the ferromagnetic yoke and a second air-gap surface to form a residual magnetic air-gap of substantially constant thickness with the fixed part, said second air-gap surface being substantially parallel to the axis of movement of the moving part,        the excitation coil enabling the position and speed of the moving part to be controlled by means of an electric control current.        
The invention also relates to an electric switch apparatus comprising at least one stationary contact operating in conjunction with at least one movable contact to switch the power supply of an electric load.